Test apparatus for testing filters or containers

ABSTRACT

A cleaning process is provided for a test apparatus that has a switch, external connections and internal volumes that can come into contact with a fluid from a filter to be tested or a container to be tested. The cleaning process includes selecting one or more internal volumes to be cleaned, cleaning the selected internal volumes with a cleaning fluid by a corresponding switching of the switch, at least partially draining the cleaning fluid left in the selected internal volumes after cleaning, and flushing the selected internal volumes with a flushing fluid different from the cleaning fluid. Also provided are a computer program product for performing the cleaning process, a cleaning apparatus, and a test apparatus for testing filters and containers.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 13/089,550, filed on Apr. 19, 2011, the contents ofwhich are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cleaning process for a testapparatus, a computer program product for performing a cleaning processaccording to the invention, a cleaning apparatus, and a test apparatusfor testing filters and/or containers.

2. Description of the Related Art

From document DE 101 36 785 A1 there is known a cleaning process for afilter test apparatus, in which the filter test apparatus is filled witha cleaning fluid. After a predetermined residence time, the contaminatedcleaning fluid is flushed out of the filter test apparatus by means offresh cleaning fluid.

Starting from the known prior art, it is an object of the invention toachieve an improved cleaning result.

This object is solved by the features of the independent claims.Preferred embodiments are the subject of the dependent claims.

SUMMARY OF THE INVENTION

An aspect of the present invention relates to a cleaning process for atest apparatus having switching means, external connections, internalvolumes, which can come into contact with a fluid from a filter to betested or a container to be tested, the cleaning process comprising thefollowing steps:

-   -   selecting one or more internal volumes to be cleaned;    -   cleaning the selected internal volumes with a cleaning fluid by        a corresponding switching of the switching means;    -   at least partially draining the cleaning fluid left in the        selected internal volumes after cleaning;    -   flushing the selected internal volumes with a flushing fluid        different from the cleaning fluid.

Advantageously, the process according to the invention leads to animproved cleaning of the internal volumes, particularly from themicrobiological point of view. Advantageously, the cleaning fluid, whichis contaminated itself during cleaning of the internal volumes, isprevented either from accumulating or remaining in the internal volumesof the test apparatus or from mixing with the subsequently suppliedcleaning fluid or flushing fluid. Particularly in the case that thecontaminations of the internal volumes contain bacteria or viruses, itis necessary to completely remove both the contaminations and thecontaminated cleaning fluid from the internal volumes of the testapparatus before the test apparatus is put into normal operation again.Moreover, the cleaning process according to the invention can beperformed more easily and more safely than cleaning processes known sofar.

In the cleaning process according to the invention, which isparticularly computer-assisted or computer-controlled, the internalvolumes to be cleaned can be selected particularly by switching of theswitching means, and particularly all or substantially all internalvolumes that can come into contact with a fluid during normal operationof the test apparatus can be cleaned. It is therefore possible to cleaninternal volumes having been contaminated or soiled by a fluid from anapparatus to be tested. Such an apparatus to be tested can be a filterapparatus or a container.

The cleaning fluid can comprise a detergent, such as dilute orconcentrated sodium hydroxide solution. Particularly, the cleaning fluidcan consist of a NaOH solution (sodium hydroxide solution or causticsoda lye) with a concentration of approx. 0.1 mol to approx. 2 mol,preferably of approx. 0.1 mol. A further preferred cleaning fluid is aH₂O₂ solution from approx. 0.33% to approx. 1%, preferably of approx.1.0% (hydrogen peroxide solution). Preferably, the cleaning fluid cancomprise a solvent, particularly an alcoholic solution or a surfactantsolution. The term “fluid” as defined by the present applicationcomprises a liquid phase, a gaseous phase, as well as a mixture thereof.Preferably, approx. 5 to 30 liters of cleaning fluid, further preferablyapprox. 6 liters, are required to clean the internal volumes.

The partial drainage of the cleaning fluid is performed by acorresponding switching of the switching means, wherein the cleaningfluid is removed from the internal volumes of the test apparatus atleast partially, preferably substantially completely. A substantiallycomplete drainage of the cleaning fluid means that the quantity ofcleaning fluid remaining in the internal volumes is preferably smallerthan approx. 5%, further preferably smaller than approx. 2%,particularly smaller than approx. 1% of the internal volumes of the testapparatus to be cleaned. The drainage is preferably performed in asuccessive manner, i.e. after the cleaning fluid has remained for apredetermined residence time after the filling of the internal volumes.The residence time may be more than approx. 10 minutes, preferably morethan approx. 20 minutes, particularly approx. 60 minutes. Thus, thesupplied cleaning fluid can take effect in the internal volumes to becleaned. The contaminations can be soaked or partially dissolved toremove them from the wall surface of the internal volumes to be cleaned.The drainage may start after the residence time has expired.

Flushing of the selected internal volumes with the flushing fluidadvantageously causes the remaining quantity of cleaning fluid to bediluted by the flushing fluid and to be substantially completely flushedor carried out of the internal volumes. The flushing fluid is differentfrom the cleaning fluid. The flushing fluid preferably consists ofdemineralized, preferably sterile water or ultrapure water. Flushing canbe performed with a predetermined flushing time of approx. 10 to 50minutes. Preferably, approx. 5 to 30 liters of flushing fluid arerequired to flush the internal volumes.

Preferably, cleaning with the cleaning fluid, draining and/or flushingwith the flushing fluid are substantially performed successively. Bysuccessively cleaning, draining and/or flushing the internal volumes tobe cleaned, a comprehensive cleaning of the internal volumes to becleaned can be ensured. Moreover, by successively draining and/orflushing the cleaning fluid off the internal volumes, it can be safelyensured that substantially no cleaning fluid is left in the respectiveinternal volume afterwards. Particularly if harmful and/or irritantand/or corrosive cleaning fluids are used, it can be advantageouslyensured that residues of the cleaning fluid do not inadvertentlycontaminate one of the filters or containers to be tested when the testapparatus is used. Preferably, the cleaning process comprises a furtherstep of at least partially draining the flushing fluid left in theflushed internal volumes after flushing.

For the selection of the internal volumes to be cleaned, drained orflushed, the cleaning process preferably comprises at least one step ofpneumatically and/or electrically switching the switching means.

Preferably, the step of draining the flushing fluid off the cleaned andflushed internal volumes is performed substantially successively bycorrespondingly switching the switching means. Preferably, the step ofdraining the flushing fluid and drying the internal volumes is performedby means of sterile compressed air or by means of a pressurized gas,particularly of an inert gas, with a pressure of greater than 100 kPa (1bar), further preferably with a pressure of greater than 200 kPa (2bar), most preferably 200 kPa (2 bar).

By drying the cleaned and flushed internal volume (preferably withcompressed air), it is ensured that substantially no cleaning fluidand/or flushing fluid is left in the cleaned internal volumes.

Preferably, the cleaning process comprises the step of:

-   -   cleaning the selected internal volumes by having a vaporous or        gaseous cleaning fluid flow through the selected internal        volumes by a corresponding switching of the switching means.

Particularly preferably, the cleaning fluid in this case comprises hotsteam having a temperature of greater than approx. 121° C., preferablygreater than approx. 134° C. Advantageously, the selected internalvolumes can be sterilized by this step. Further preferably, the step ofsterilizing using hot steam is performed after the flushing fluid hasbeen drained off the internal volumes or after the selected internalvolumes have substantially fallen dry. Further preferably, thesterilization with the vaporous or gaseous cleaning fluid can befollowed by drainage of the cleaning fluid, particularly by means of asterile gas, for example sterile compressed air.

An aspect of the present invention relates to a particularlycomputer-assisted or computer-controlled cleaning process for a testapparatus having switching means, external connections, internalvolumes, which can come into contact with a fluid from an apparatus tobe tested, the cleaning process comprising the following steps:

-   -   selecting one or more internal volumes to be cleaned;    -   cleaning the selected internal volumes by having a vaporous or        gaseous cleaning fluid flow through the selected internal        volumes by a corresponding switching of the switching means;    -   draining the cleaning fluid left in the selected internal        volumes after cleaning.

The cleaning fluid may be vaporous or gaseous. To prevent the cleaningfluid from condensing within the internal volumes, the flow of thecleaning fluid through the selected internal volumes is enabled by acorresponding switching of the switching means. Accordingly, a supply ofcleaning fluid into and drainage of the cleaning fluid off the selectedinternal volumes take place at the same time. Advantageously, if avaporous or gaseous cleaning fluid is used, the quantity of the cleaningfluid left in the internal volumes is limited to the proportion ofcleaning fluid condensed in the internal volumes. Furtheradvantageously, no flushing of the internal volumes by means of aflushing fluid is necessary for a low degree of condensation. Forexample, ozone may be used as a gaseous cleaning fluid, which allowssafely killing microbiological organisms and substantially does notaccumulate or remain within the internal volumes of the test apparatus.Preferably, draining of the cleaning fluid off the internal volumes canbe followed by flushing, preferably with a flushing fluid different fromthe cleaning fluid. If a vaporous or gaseous cleaning fluid is used,flushing can also be performed with the liquid phase of the cleaningfluid as the flushing fluid.

Preferably, the cleaning fluid is a hot steam having a temperature ofgreater than approx. 121° C., preferably greater than approx. 134° C.Due to the preferred use of hot water vapor, the hot steam has apositive pressure of approx. 100 kPa (approx. 1 bar) and a positivepressure of approx. 200 kPa (approx. 2 bar) at a temperature of approx.121° C. and a temperature of approx. 134° C., respectively.

Further preferably, the hot steam is generated from demineralized water.Advantageously, the cleaning fluid condenses to pure water within theselected internal volumes, so that flushing with a flushing fluid isusually not required. Preferably, however, flushing with a flushingfluid, for example demineralized water, can be performed. According tothe invention, hot steam and water are considered to be mutuallydifferent fluids. To also achieve a sterilization of the internalvolumes in addition to the cleaning, the hot steam is preferablysupplied such that the temperature within the internal volumes is atleast 121° C. at any point. In order to monitor that this temperature ismaintained, a temperature sensor is preferably provided at a point ofthe internal volumes which has the substantially greatest heatabsorption capacity and thus probably the lowest temperature duringcleaning with hot steam. This point can preferably be in the region of acleaning fluid outlet. Further preferably, particularly forconfigurations of the internal volumes in which the cleaning fluidoutlet is not the coldest point within the internal volumes, for exampleif the outlet is arranged close to the inlet and the inlet temperatureis quickly reached by heat conduction at the outlet, the temperaturesensor can preferably be arranged in difficult-to-access regions in orat which fluid has accumulated, as the case may be.

Preferably, the step of draining the cleaning fluid and/or the flushingfluid comprises a step of at least partially drying the cleaned and/orflushed internal volumes. Draining can be performed by a correspondingswitching of the switching means.

Preferably, the step of drying is performed using compressed air,preferably using sterile compressed air. Preferably, the compressed airhas a positive pressure of at least approx. 100 kPa (1 bar) with respectto the atmospheric pressure, further preferably a pressure of greaterthan 200 kPa (2 bar), particularly preferably 200 kPa (2 bar). The stepof drying of the cleaned or flushed internal volumes is performedpreferably substantially successively by a corresponding switching ofthe switching means. By drying of the cleaned or flushed internalvolumes, it is ensured that substantially no cleaning fluid or noflushing fluid is left in the cleaned or flushed internal volumes.

Preferably, the cleaning process further comprises the steps of:

-   -   collecting the cleaning fluid and/or flushing fluid exiting the        selected internal volumes;    -   separating the collected cleaning fluid and/or the flushing        fluid into a liquid phase and a gaseous phase, wherein the        liquid phase is collected in an receiving container, and the        gaseous phase escapes into the environment.

Collecting of the cleaning fluid and/or flushing fluid exiting the testapparatus during cleaning and/or draining is preferably performed bymeans of at least one fluid discharge line, which guides the exitingfluids to a collecting apparatus. The collecting apparatus can comprisea collecting container, in which the exiting and optionally contaminatedfluids are collected. The collecting container is preferably formed as aso-called “sterile receiver”, so that a sterile fluidic connectionbetween the test apparatus, the cleaning apparatus, and the collectingcontainer can be established. Due to the quantity of the requiredcleaning fluid or flushing fluid, the collecting container preferablyhas a volumetric capacity of more than approx. 10 liters, furtherpreferably of more than approx. 20 liters, and particularly of more thanapprox. 60 liters. Preferably, the collecting container has at least onecheck valve, which prevents fluids from escaping from the collectingcontainer toward the test apparatus or into the environment through theconnected at least one fluid discharge line. If a vaporous or gaseouscleaning fluid or flushing fluid is used, the fluid supplied to thecollecting apparatus is separated into a liquid phase and a gaseousphase, usually by condensation e.g. on a cooling element, a coolingcoil, etc. The gaseous phase can escape into the environment via avalve, for example a pressure relief valve or a check valve.

Preferably, the gaseous phase escapes via a bacteria-retaining apparatusand/or via a virus-retaining apparatus. Particularly if the internalvolumes of the test apparatus are contaminated with pathogenic germs andthus the cleaning fluid and/or the flushing fluid might containpathogenic germs as well, the bacteria-retaining apparatus and/or thevirus-retaining apparatus prevents these germs from escaping or exitinginto the environment.

Preferably, the cleaning process comprises the step of logging thecourse of the cleaning process, for example by storage on a datacarrier, by generating a printout of a cleaning protocol, or bytransmitting the cleaning protocol over a data line.

Computer Program Product

An aspect of the present invention relates to a computer programproduct, particularly embodied as a signal and/or as a data stream,comprising computer-readable instructions, wherein the instructionsperform a process according to the invention when loaded and executed ona suitable computer system. In other words, a computer program productis provided which comprises program parts for performing the processaccording to the invention or a preferred embodiment thereof. Further, acomputer program is provided which, when loaded on a computer, canperform the process according to the invention or a preferred embodimentthereof. Further, a computer-readable storage medium is provided onwhich such a computer program is stored.

Cleaning Apparatus

An aspect of the present invention relates to a cleaning apparatus for atest apparatus, comprising:

-   -   at least one fluid connection for a container for a cleaning        fluid, wherein the fluid connection is fluidically coupled with        a complementary or mating connection via a fluid supply line,        wherein the complementary connection can be fluidically coupled        with an external connection of the test apparatus, and    -   at least one fluid connection for a container for a flushing        fluid, wherein the fluid connection is fluidically connected        with the complementary connection via a fluid supply line;    -   at least one apparatus for delivering a cleaning fluid and/or a        flushing fluid from one of the containers to the complementary        connection; and    -   at least one connection for a collecting apparatus for        collecting the cleaning fluid and/or flushing fluid exiting the        test apparatus, wherein the collecting apparatus can be coupled        with at least one external connection of the test apparatus by        means of at least one fluid discharge line.

Advantageously, the cleaning apparatus can be handled more easily andsafely and achieves an improved cleaning of the test apparatus. Thecleaning apparatus comprises at least one fluid connection, preferablytwo fluid connections, for a cleaning fluid container and a flushingfluid container. It is understood that in addition to or instead of thefluid connections for the containers, the cleaning apparatus can alsocomprise the containers themselves. The corresponding fluid connectionswould then be internal fluid connections, which fluidically couple thecleaning fluid container and the flushing fluid container with theassociated fluid supply lines. The fluid supply line is fluidicallyconnected with the complementary connection, which can preferably beformed as a complementary plug-in nipple or a complementary plug-incoupling, which can be fluidically connected with an associated plug-incoupling or an associated plug-in nipple of one of the externalconnections of the test apparatus. It is understood that for practicalpurposes, a cleaning fluid container and a flushing fluid container areconnected with an associated fluid connection at the beginning of thecleaning process to advantageously perform the entire cleaning processwithout decoupling or coupling fluid lines or fluid connections.However, merely a single fluid connection can be provided, whichsequentially serves as a fluid connection for the cleaning fluidcontainer and then as a fluid connection for the flushing fluidcontainer, wherein while the cleaning process is performed, the cleaningfluid container has to be separated from the fluid connection tosubsequently connect the flushing fluid container thereto.

The at least one apparatus for delivering the cleaning fluid and/or theflushing fluid is preferably designed or configured such as to deliverboth the cleaning fluid and the flushing fluid from the correspondingcontainer to the complementary connection of the cleaning apparatus andfurther via the external connection coupled therewith into the internalvolumes of the test apparatus to be cleaned. Preferably, two deliveringapparatuses can be provided, wherein the first delivering apparatus isdesigned to deliver the cleaning fluid, and the second deliveringapparatus is designed to deliver the flushing fluid. The at least onedelivering apparatus can be configured as a pump, particularly as aflexible-tube pump.

The cleaning apparatus comprises at least one connection for acollecting apparatus, or preferably the collecting apparatus itself,wherein the connection for the collecting apparatus then is an internalconnection of the cleaning apparatus. The collecting apparatus cancomprise a collecting container for collecting the cleaning fluid orflushing fluid exiting the test apparatus, wherein the collectingapparatus or the collecting container is coupled with an externalconnection or multiple external connections of the test apparatus viaone or more fluid discharge line(s) during normal operation.

Preferably, the cleaning apparatus comprises at least one switchingmeans controlling the fluid flow through one of the fluid supply linesand/or controlling the fluid flow through one of the at least one fluiddischarge lines. Further preferably, the switching means comprisepneumatic switching means and/or electromagnetic switching means. Forexample, the switching means can be configured as valves, i.e. switchingvalves or proportional valves, which can be actuated electrically,electromagnetically and/or pneumatically. Preferably, the valves used,e.g. bellows or diaphragm valves, have a small valve volume ofpreferably less than approx. 10 ml, particularly of less than approx. 1ml. Particularly, the switching means can be computer-controlled, sothat the switching operations for initiating different steps of thecleaning process are advantageously performed automatically, i.e.without any user action or user interaction.

Preferably, the apparatus for delivering the cleaning fluid and/or theflushing fluid can be operated with compressed air or pressurized gas.Particularly, the delivery is performed by pressurizing the containerfor cleaning fluid or the container for flushing fluid. Due to thepositive pressure in the container(s), the fluid contained therein canbe delivered via a rising pipe.

An aspect of the present invention relates to a cleaning apparatus for atest apparatus, comprising:

-   -   an apparatus for providing a vaporous or gaseous cleaning fluid,        which can be coupled with an external connection of the test        apparatus by means of a cleaning fluid supply line;    -   at least one connection for a separating apparatus for        separating the cleaning fluid exiting the test apparatus into a        liquid phase and a gaseous phase,        wherein the separating apparatus can be coupled with at least        one external connection of the test apparatus by means of a        fluid discharge line, and        wherein the liquid phase arising in the separating apparatus is        collectable in a collecting container, and the gaseous phase        arising in the separating apparatus escapes into the        environment.

The apparatus for providing a vaporous or gaseous cleaning fluid canpreferably comprise an apparatus for producing the vaporous or gaseouscleaning fluid. Moreover, alternatively or in addition to the connectionfor the separating apparatus, the cleaning apparatus can also comprisethe separating apparatus itself. A preferred separating apparatus is acondensation apparatus, such as a cooling element or a cooling coil. Theliquid phase arising in the separating apparatus can be collected in acollecting container. Preferably, the collecting container has at leastone check valve, so that no fluids from the collecting container can getback into the test apparatus. The gaseous phase can escape into theenvironment preferably via a valve, for example a pressure relief valveor a check valve, optionally via a filter, a bacteria-retainingapparatus and/or a virus-retaining apparatus.

Preferably, the apparatus for providing the cleaning fluid comprises ahot steam generator generating a hot steam having a temperature ofgreater than approx. 121° C. Further preferably, the hot steam isgenerated from demineralized water. Due to the preferred use of hotwater vapor, the hot steam has a positive pressure of approx. 100 kPa(>1 bar) at a temperature of greater than approx. 121° C. At a furtherpreferred temperature of greater than approx. 134° C., the positivepressure is greater than approx. 200 kPa (>2 bar). In order to monitorthat the preferred minimum temperature of approx. 120° C. is maintainedwhen sterilizing the internal volumes, preferably at least onetemperature sensor and/or at least one pressure sensor is/are providedwithin the internal volumes. Preferably, at least one of the temperatureand/or at least one of the pressure sensors is arranged in the region ofa cleaning fluid outlet.

Preferably, the cleaning apparatus comprises a bacteria-retainingapparatus and/or a virus-retaining apparatus, via which the gaseousphase escapes into the environment.

Preferably, the cleaning apparatus comprises an apparatus for providingcompressed air, preferably sterile compressed air, wherein thecompressed air can be supplied to the compressed air supply connectionof the test apparatus via a compressed air supply line connection. Thecompressed air can be used to deliver fluids within the cleaningapparatus and/or the test apparatus connected therewith. Moreover, atleast one external connection of the test apparatus is configured suchthat a compressed air supply line for drying the cleaned or flushedinternal volumes is connectable therewith. Thus, drying of the cleanedinternal volumes can be performed with compressed air having a suitablepressure, preferably a positive pressure of greater than approx. 100 kPa(>1 bar), further preferably a pressure of greater than 200 kPa (2 bar),particularly preferably 200 kPa (2 bar). Particularly, the compressedair can be supplied to the test apparatus via a compressed air supplyline connection of the cleaning apparatus.

Preferably, the apparatus for providing compressed air is pneumaticallycoupled with the apparatus for delivering the cleaning fluid and/or theflushing fluid. Further preferably, the apparatus for providingcompressed air is coupled with pneumatically actuatable switching meansof the cleaning apparatus. Advantageously, an additional deliveringapparatus for the cleaning fluid or for the flushing fluid, such as aninternal or internal pump, can be omitted. By omitting an external pump,the safety in performing the cleaning process is advantageouslyincreased, since fluid couplings or tubes are prevented from coming off.Particularly if a corrosive cleaning fluid is used, the risk of workaccidents can be reduced.

Preferably, the cleaning apparatus comprises a connection devicecomprising at least two complementary or mating external connections ofthe cleaning apparatus. The compressed air supply line connection, thecomplementary connection for supplying the cleaning or the flushingfluid, the at least one fluid discharge connection, and the compressedair connection can be part of a connection device as complementaryexternal connections of the cleaning apparatus, which are configuredcomplementarily to the corresponding external connections of the testapparatus. The connection device can preferably cause the geometricdistances of the individual, complementary external connections toremain constant to each other. In other words, the individual,complementary external connections are spatially fixed or fixable withrespect to each other. Preferably, the connection device can be arrangedon the test apparatus by a displacement movement such that thecomplementary external connections of the connection device cansubstantially simultaneously be coupled with the associated externalconnections of the test apparatus. Advantageously, the requiredconnections can be established more quickly, wherein erroneous couplingof the individual connections is prevented in addition. Furtherpreferably, the work safety during the process is increased, since fluidcouplings or tubes are prevented from coming off.

Further preferably, the connection device comprises a connector of thecleaning apparatus, which is configured to be electrically coupled witha mating complementary connector of the test apparatus. Preferably,electrical coupling can be performed by displacing the cleaningapparatus along a connection direction A, particularly by a lineardisplacement. Particularly, the connector or the connection device canbe designed or configured for an interface, for example a RS232interface, a RS435 interface, a RJ45 interface, and/or a USB interface.Further preferably, the connection device can have a connector for theelectric power supply of the cleaning apparatus via the test apparatus.Advantageously, a power supply in the cleaning apparatus can be omittedthen.

Test Apparatus

An aspect of the present invention relates to a test apparatus fortesting filters and/or containers, comprising:

-   -   switching means;    -   external connections;    -   internal volumes, which can come into contact with a fluid from        a filter or container to be tested;        wherein the switching means themselves and the switching means        and the external connections are fluidically coupled via the        internal volumes, and        wherein the internal volumes of the test apparatus are arranged        such that the internal volumes can be substantially completely        drained via one of the external connections, which is arranged        at the lowest point with respect to the internal volumes.

Advantageously, the test apparatus can be handled more easily and safelyand particularly be cleaned more easily and better. Preferably, theswitching means of the test apparatus comprise pneumatic switching meansand/or electromagnetic switching means. For example, the switching meanscan be configured as valves, i.e. switching valves or proportionalvalves, which can be actuated electrically, electromagnetically and/orpneumatically. Preferably, the valves used, e.g. bellows or diaphragmvalves, have a small valve volume of preferably less than approx. 10 ml,particularly of less than approx. 1 ml. Particularly, the switchingmeans can be computer-controlled, so that the switching operations forinitiating different steps of the cleaning process are advantageouslyperformed automatically, i.e. without any user action.

At least one external connection is configured such that a cleaningfluid or a flushing fluid can be supplied to the test apparatus therebyin order to clean selected internal volumes. Thus, the cleaningapparatus can be coupled with the test apparatus to be cleaned in aneasy and safe manner. Furthermore, at least one external connection isconfigured such that the supplied cleaning fluid or flushing fluid canbe discharged or removed thereby.

Further preferably, at least one of the external connections isconfigured such that a source of compressed air for drying the cleanedor flushed internal volumes can be coupled therewith. Thus, drying ofthe cleaned internal volumes can be performed using compressed air.

The internal volumes can comprise coupling lines between the switchingmeans, coupling lines between the switching means and the externalconnections, volumes in the switching means, preferably an internalreference tank, and coupling lines between the internal reference tankand at least one switching means or at least one external connection.Preferably, the internal volumes are defined from parts and/or linescomprising walls of stainless steel and/or Teflon.

Particularly, the switching means, the coupling lines, and the externalconnections, which define the internal volumes, can be drainedsubstantially completely. Particularly, in normal operation, thecoupling lines are sloped with respect to the horizontal defined by thefield of gravity of the earth, preferably at an angle of greater thanapprox. 1 degree, further preferably greater than approx. 5 degrees.

One of the external connections is arranged at the lowest point withrespect to the internal volumes during normal operation of the testapparatus to enable a substantially complete drainage of the internalvolumes via this external connection.

Preferably, the internal volumes are arranged such that the path fromthe lowest point of the internal volumes to an arbitrary further pointwithin the internal volumes increases steadily opposite to the directionof gravity in parts, or has a constant height with respect to thedirection of gravity at least in parts.

Preferred embodiments of the present invention will be explained in thefollowing by way of example on the basis of the accompanying drawings.Individual features of the illustrated preferred embodiments can becombined to further preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a schematic structure of a preferred embodiment of a testapparatus for testing filters and/or sterile disposable containers.

FIG. 2 a schematic structure of a preferred embodiment of a cleaningapparatus for a test apparatus for testing filters and/or steriledisposable containers.

FIG. 3 a flow diagram of a preferred cleaning process.

FIG. 4 a schematic structure of the embodiment of the cleaning apparatusduring a drying step.

FIG. 5 a schematic structure of a preferred embodiment of a cleaningapparatus for a test apparatus.

FIG. 6 a flow diagram of a preferred cleaning process.

FIG. 7 a a perspective view of a preferred embodiment of a testapparatus.

FIG. 7 b a side view of the preferred embodiment of the test apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a schematic structure of a preferred embodiment of a testapparatus 1 for testing filters 5 or for testing the pressure tightnessof containers 7, particularly sterile disposable containers.

The test apparatus 1 comprises valves 11, 12, 13, 14, 15, which areparticularly designed as switching valves, and at least one proportionalvalve 16. Furthermore, the test apparatus 1 comprises externalconnections 21, 23, 25, 27, 29, wherein the external connectionscomprise a compressed air supply connection 21, through which compressedair is supplied during the test operation, a connection 23 for internalventilation, a connection 25 for external ventilation, a test connection27 for connection of an apparatus to be tested, for example a filter 5to be tested or a filter apparatus to be tested or a container 7 to betested, and a connection 29 for an external reference tank 31.Preferably, an internal reference tank 33 is provided in the testapparatus 1. The valves 11, 12, 13, 14, are fluidically coupled witheach other via coupling lines 35, 37, 39, 41, i.e. a fluid can flow fromone of the switching valves 11, 12, 13, 14, 15 to another one throughthe coupling lines 35, 37, 39, 41. Furthermore, the valves 11, 12, 13,14, 15 are fluidically coupled with the respective mating externalconnections 23, 25, 27 via coupling lines 43, 47, 45. The internalreference tank 33 is coupled with the valve 12 via a coupling line 49,and hydraulically coupled or fluidically coupled with the connection 29for the external reference tank 31 via a coupling line 51. Furthermore,the test apparatus 1 preferably comprises a pressure gauge 53, which ishydraulically coupled or fluidically coupled with the coupling line 35via a coupling line 55.

The valves 11, 12, 13, 14, 15 are preferably bellows or diaphragm valvesand preferably have a small valve volume V₁₁, V₁₂, V₁₃, V₁₄, V₁₅, forexample a valve volume of less than approx. 5 ml, preferably of lessthan approx. 1 ml.

The coupling lines 35, 49, 51, 43, 47, 45, 37, 39, 41, 55, the internalreference tank 33, and the internal volumes V₁₁, V₁₂, V₁₃, V₁₄, V₁₅ ofthe valves 11, 12, 13, 14, 15 will be referred to as internal volumes inthe following. Furthermore, the following exemplary description of apreferred embodiment of the present invention is made with respect to atest apparatus 1 comprising only one proportional valve 16.

During the testing of for example a filter 5, e.g. a membrane filter,the internal reference tank 33 is filled with compressed air having apredetermined or predeterminable pressure. This may be done via theexternal reference tank 31 or via the compressed air supply connection21 and the proportional valve 16. During a subsequent measurement, it isdetermined by means of the reference tank 33 and the pressure gauge 53how large the pressure drop in the filter 5 is. Since the pressure dropdepends on the degree of clogging of the continuous filter membrane porespace, the quality of the filter 5 can thus be determined. In the sameor similar way, the pressure tightness of containers 7, particularlysterile disposable containers 7 and sterile flexible bags 7, can betested. To this end, for example a flexible sterile disposable bag 7 canbe arranged between two holding elements 9, which allow the inflation ofthe disposable bag 7 due to pressurization only to a predetermined orpredeterminable volume. If the detected pressure drop after theinflation of the disposable bag 7 is below a predetermined orpredeterminable threshold value, the disposable bag is sufficientlytight or is considered to be sufficiently tight.

As part of the test, the filter 5 to be tested or the filter device tobe tested or the container 7 to be tested preferably is to be validatedas well, i.e. the quality of the filter 5 is to be determined on thebasis of predetermined or predeterminable standards. To this end, thetest apparatus 1 is preferably connected to the soiled side of thefilter 5, i.e. the side to which a fluid to be filtered is suppliedduring normal operation. However, during the test it may happen that theunfiltered and thus soiled fluid enters the test apparatus 1, inparticular its internal volumes, due to a backflow. However, for avalidatable testing, it is necessary to ensure that the test apparatus 1is not contaminated, e.g. with bacteria, viruses, and othercontaminations, before each new test process. It is thus required tothoroughly clean the test apparatus 1 preferably before each testprocess. To further allow an even safer cleaning, the internal volumesare preferably defined by parts or lines that are substantiallycompletely made of stainless steel or a FDA-conform material (FDA: USFood and Drug Administration), for example Teflon.

Furthermore, to prevent fluid from remaining in the internal volumes ofthe test apparatus 1 or to keep it as little as possible, the internalvolumes are preferably arranged according to a hygienic design.

The term “hygienic design” means that the test apparatus can be keptsubstantially free from vegetative microorganisms, wherein it can bedefined thereby that the microbiological failure rate remains withinpredetermined or predeterminable limits. A predominant pathogen may beAspergillus niger, a mold fungus, which is capable of decomposing allorganic materials and even glass. Aspergillus niger is often used in thefood industry to produce citric acid. The fungus tolerates pH rangesfrom 1.5 to 9.8 and is thus capable of existing both in strongly acidicand alkaline milieus. The cleaning process, the cleaning apparatusand/or the test apparatus are preferably designed such that acontamination with this predominant pathogen is substantially completelyremoved.

In other words, the internal volumes are arranged such that asubstantially complete drainage of the internal volumes is possible viaone of the external connections 23, 25, 27, 29. To this end, preferablyone of the external connections 23, 25, 27, 29 is arranged such that itis located at the lowest point with respect to the internal volumesduring normal operation of the test apparatus 1. Moreover, preferablyall further internal volumes are arranged such that the path from thelowest point of the internal volumes to an arbitrary further pointwithin the internal volumes rises steadily in parts opposite to thedirection of gravity or has at least a constant height in parts oppositeto the direction of gravity. Thus, it is ensured that fluid-filledinternal volumes can be drained via an external connection 23, 25, 27,29 due to the effect of gravity on the fluid.

Further preferably, the internal volumes can be drained by means ofcompressed air or by means of gas with excess pressure (particularlyinert gas), which is provided at the compressed air supply connection21. Particularly preferably, the drainage in the embodiment shown inFIG. 1 can then be performed via the test connection 27. To ensure asubstantially complete drainage of the internal volumes in this case,the dead volumes, i.e. the internal volumes, which are substantially notflown through by compressed air over the path from the compressed airsupply connection 21 to the test connection 27, are minimized,particularly preferably zero. In particular, the dead volume of thecoupling line 37 is minimized, particularly substantially zero. The termsubstantially zero particularly means that the line length of thecoupling line 37 between the valve 12 and the coupling line 35 issmaller or shorter than the diameter of the coupling line 37,particularly smaller than approx. 1 mm. Thereby, it is advantageouslyprevented that fluid remains in the coupling line 37 during draining ofthe internal volumes, for example due to capillary forces. Preferably,the dead volume of the coupling line 55 between the pressure gauge 53and the coupling line 35 is also substantially zero.

The drainage of the internal volumes can alternatively or in addition beperformed via the connection 29 for an external reference tank.Advantageously, the connection 29 can represent the highest point in thefluidically interconnected system of the internal volumes as a rule.

FIG. 2 shows the schematic structure of a preferred embodiment of acleaning apparatus 3 for a test apparatus 1 for testing filters and/orsterile disposable containers. The cleaning apparatus 3 can comprise afluid connection 57 and preferably a compressed air connection 59 for apressure container 61, wherein the pressure container 61 contains acleaning fluid 63 or a flushing fluid 65 during normal operation.Preferably, as is shown in FIG. 2, the fluid connection 57 or thecompressed air connection 59 may also be connections of external lineslocated outside a preferred housing 4 of the cleaning apparatus 3. Thepressure container 61 comprises a compressed air intake 67, which can becoupled with the compressed air connection 59, and a fluid exit 69,which can be coupled with the fluid connection 57, wherein a riser tube71 is fluidically coupled with the fluid exit 69. The riser tube 71preferably extends down to the bottom of the pressure container 61. Ifthe pressure container 61 is fed with compressed air via the compressedair intake 67, excess pressure builds up within the pressure container61, due to which the cleaning fluid 63 or flushing fluid 65 contained inthe pressure container 61 rises within the riser tube to escape from thepressure container 61 through the fluid exit 69.

For the normal operation of the cleaning apparatus 3, the fluid exit 69of the pressure container 61 can be fluidically coupled with one of theexternal connections 23, 25, 27, 29 of the test apparatus 1 via thefluid connection 57 and a fluid supply line 73, wherein the connectioncan preferably be established by means of a complementary connection 75,for example by means of a plug-in nipple or a plug-in coupling. Thefluid supply line 73 can be formed as an external line. Alternatively,the fluid connection 57 and the complementary connection 75 can bearranged or formed on or in the housing 4 of the cleaning apparatus 3,so that the fluid supply line 73 is arranged within the housing 4 of thecleaning apparatus 3. Preferably, the cleaning apparatus 3 has atemperature and/or a pressure sensor (not shown), which is/are thermallyand/or fluidically coupled with the external connection 23, 25, 27, 29of the test apparatus 1 in order to detect the temperature and/or thepressure of the supplied cleaning fluid 63. Particularly, the pressuresensor can be fluidically coupled with the fluid supply line 73, whereinthe fluid supply line 73 is preferably arranged within the housing 4 ofthe cleaning apparatus 3. In order to supply compressed air to thepressure container 61, the compressed air intake 67 of the pressurecontainer 61 can be connected with a compressed air source 77.Preferably, the compressed air intake 67 of the pressure container 61 isfluidically coupled with the compressed air source 77 via a compressedair supply line 79, a pressure reducer 81, and a compressed air valve82. As is shown, the compressed air line 79 may be an external linehaving a compressed air inlet 85, which can be coupled with a compressedair outlet 86 of the pressure valve 82. Alternatively, the compressedair line 79 can be arranged within the housing 4 of the cleaningapparatus 3, wherein then particularly the compressed air connection 59is also arranged in or on the housing, and particularly the compressedair inlet 85 and the compressed air outlet 86 may be internalconnections within the housing 4. Alternatively or in addition to thepressure reducer 81, the pressure reduction can be performed by means ofreducing the cross section of the compressed air line 79. Particularly,the compressed air source 77 can be the same compressed air source 77that provides the compressed air at the compressed air supply connection21 of the test apparatus 1. Here, a T-connection 83 can be arrangedbetween the compressed air source 77 and the compressed air supplyconnection 21, so that the compressed air supply connection 21 and thecompressed air intake 67 together are fluidically coupled with thepressure source 77. It is understood that both the pressure reducer 81and the T-connection 83 can be part of the cleaning apparatus 3, i.e.for example can be arranged at least partially in the housing 4 withother components of the cleaning apparatus 3. In this case, the cleaningapparatus 3 preferably has a primary compressed air inlet, which can befluidically coupled with the compressed air source 77, and a compressedair supply line connection 84, which can be fluidically coupled with thecompressed air supply connection 21 of the test apparatus 1. Preferably,the housing 4 of the cleaning apparatus 3 can have a compressed airoutlet 86 to which an external compressed air supply connection 79 canbe coupled. Alternatively, the pressure reducer 81 and/or theT-connection 83 can be designed as external components, wherein thecompressed air is supplied to the compressed air inlet 85 of thecleaning apparatus 3 or the compressed air inlet 85 of the compressedair supply line 79 in a reduced or unreduced form, the inlet beingfluidically coupled with the compressed air supply line 79. Thecompressed air supply connection 21 of the test apparatus 1 can becoupled with a compressed air supply line connection 84 of a compressedair line, which is fluidically coupled with the T-connection 83 or thecompressed air outlet of the cleaning apparatus 3. Alternatively, thecompressed air supply connection 21 can be coupled with a compressed airsupply line connection 84 that is formed as the compressed air outlet ofthe cleaning apparatus 3. The test apparatus 1 can be supplied withcompressed air via the compressed air supply line connection 84. Furtherpreferably, the compressed air source 77 produces a pressure of approx.500 to approx. 900 kPa (5 to 9 bar), which is applied to the compressedair supply connection 21 of the test apparatus 1. The pressure reducer81 or the compressed air line 79 is/are preferably designed such that atthe compressed air inlet 85 of the cleaning apparatus 3 or thecompressed air intake 67 of the pressure container merely a pressure ofapprox. 100 to approx. 200 kPa (1 to 2 bar), further preferably apressure of approx. 200 kPa (2 bar), is applied.

Further preferably, the cleaning apparatus 3 comprises a pressure sensor130, which is preferably fluidically coupled with the T-connection 83 todetect or measure the pressure of the compressed air provided by thecompressed air source 77. The pressure sensor 130 can at least partiallybe arranged within the housing 4 or be formed as an external pressuresensor 130. Advantageously, it can de determined by means of thepressure sensor 130 whether the compressed air source 77 provides thepreferred pressure of approx. 500 kPa to approx. 900 kPa. Thereby, thepressure of the compressed air required for a safe operation of the testapparatus 1 and the cleaning apparatus 3 can advantageously be detectedand monitored. Further preferably, on the assumption that no pressuredrops occur in the pressure container 61 and in the fluid supply line73, the pressure sensor 130 can also be used to determine the pressureof the fluid supplied to the test apparatus 1.

The cleaning apparatus 3 further comprises at least one connection 87 a,87 b, 87 c for a collecting container 89, which during normal operationcollects the fluids exiting or flowing out of the internal volumes 35,49, 51, 43, 47, 45, 37, 39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅. Atleast one of the connections 87 a, 87 b, 87 c can preferably be arrangedor formed in or on the housing 4 of the cleaning apparatus 3. Thecollecting container 89 comprises at least one fluid supply 91 a, 91 b,91 c and a vent 93. For the normal operation of the cleaning apparatus3, the at least one fluid supply 91 a, 91 b, 91 c of the collectingcontainer 89 can be fluidically coupled with one of the externalconnections 23, 25, 27, 29 of the test apparatus 1 via at least onefluid discharge line 95 a and one fluid discharge connection 97 a,wherein the fluid discharge connection 97 a is preferably a connectionthat is complementary to the respective external connection 23, 25, 27,29, for example a plug-in nipple or a plug-in coupling. It is understoodthat also a plurality of external connections 23, 25, 27, 29 of the testapparatus 1 can be coupled with an associated fluid supply 91 a, 91 b,91 c of the collecting container 89 via an associated fluid dischargeline 95 a, 95 b, 95 c via fluid discharge connections 97 a, 97 b, 97 c.

To advantageously prevent excess pressure from building up in thecollecting container 89, a vent 93 is provided to allow the gaseousphase of the fluid supplied to the collecting container 89 and the airor gas displaced by the fluid in the connecting container to escape intothe environment. To prevent the test apparatus 1 from being contaminatedby a fluid flowing back from the collecting container 89, the fluidsupplies 91 a, 91 b, 91 c are preferably provided with a check valve.Particularly preferably, the fluid supplies 91 a, 91 b, 91 c are formedas plug-in nipples or plug-in couplings, which each have a closure valveand/or a check valve. Alternatively or in addition, a closure valveand/or a check valve can be arranged in a complementary plug-in couplingor a complementary plug-in nipple of the connections 87 a, 87 b, 87 c ofthe fluid discharge lines 95 a, 95 b, 95 c. Further preferably, abacteria-retaining apparatus or a virus-retaining apparatus 101 isarranged downstream of the vent 93 to advantageously prevent theenvironment from being contaminated by pathogenic germs exiting the testapparatus. The bacteria-retaining apparatus or the virus-retainingapparatus 101 can be fluidically coupled with the vent 93 by means of aretaining apparatus connection 88, particularly be fluidically coupledin a sterile manner. Preferably, the bacteria-retaining apparatus or thevirus-retaining apparatus 101 is at least partially arranged within thehousing 4 of the cleaning apparatus 3, as is shown in FIG. 2, whereinthe retaining apparatus connection 88 is preferably arranged or formedin or on the housing 4. Alternatively, the bacteria or virus-retainingapparatus 101 can also be arranged as an external apparatus outside thehousing.

FIG. 3 shows a flow diagram of a preferred cleaning process withreference to FIGS. 1 and 2. At the beginning of cleaning, the testapparatus 1 is in a normal state, wherein the switching valves 11, 14and the proportional valve 16 are closed and the switching valves 12,13, 15 are open. In an initialization step S10, a pressure container 61is filled with a cleaning fluid 63 and the test apparatus 1 is put intoa start state for cleaning, wherein the switching valves 11, 12, 13, 14and the proportional valve 16 are closed, while the switching valve 15remains open.

In a subsequent step S14 of the cleaning process, the cleaning apparatus3 is provided and the compressed air valve 82 of the cleaning apparatus3 is closed. Subsequently, the compressed air source 77 is coupled withthe compressed air supply connection 21 of the test apparatus 1, thecomplementary connection 75 of the fluid supply line 73 is connectedwith the external connection 23 of the test apparatus 1, and the fluiddischarge lines 95 a, 95 b, 95 c is connected with the externalconnections 25, 27, 29 via the fluid connections 97 a, 97 b, 97 c of thecleaning apparatus 3 during a process step S16. In a further processstep S18, the user is asked to confirm the correct connection of thecleaning apparatus 3 with the test apparatus 1 and to start the cleaningof the test apparatus 1, for example by operating a start button.

After cleaning has been started, the compressed air valve 82 is openedin a step S20, so that compressed air enters the pressure container 61from the compressed air source 77 via the T-connection 83, the pressurereducer 81, the compressed air valve 82, and the compressed air line 79.Thereby, excess pressure builds up within the pressure container 61,which preferably is approx. 1 to 2 bar, further preferably approx. 2bar. In a further step S22, preferably after a predetermined orpredeterminable operating pressure within the pressure container 61 hasbeen reached, the user is asked to confirm the proper state of the testapparatus 1 and the cleaning apparatus 3. Particularly, the user cancheck during this step whether a leakage occurred in the cleaningapparatus 3 with excess pressure.

After the confirmation, the actual cleaning process or the actualcleaning steps are performed. In a step S24, the switching valves 12, 13are opened and the switching valve 15 is closed to fill the internalreference tank 33 with the cleaning fluid 63 from the pressure container61. In doing so, due to the excess pressure in the pressure container61, i.e. by pneumatic conveyance, the cleaning fluid 63 rises throughthe riser pipe 71 via the fluid supply line 73 to the externalconnection 23 for internal ventilation of the test apparatus 1. Startingfrom the external connection 23, the cleaning fluid 63 flows to theinternal reference tank 33 via the line 43, the switching valve 13, thelines 39, 35, 37, the switching valve 12, and the line 49. From there,the cleaning fluid 63 can flow further via the line 51 and from theexternal connection out of the test apparatus. Filling of the internalreference tank 33 is preferably determined by means of a predeterminedor predeterminable filling time T24.

Subsequently, after the internal reference tank 33 has been filled,filling of the external connection 27, which is adapted for connectionof a filter 5 or a container 7, is performed in a step S26. To this end,in step S26, the switching valve 12 is closed and the switching valve 14is opened, so that the cleaning fluid 63 can flow to the externalconnection 27 via the line 35, the switching valve 14, and the line 47.Preferably, the filling process is time-controlled and thus terminatedafter a predeterminable filling time T26. Finally, in a step S28, theremaining part of the internal volumes, i.e. the line 41, the switchingvalve 15, and the line 45, are filled with the cleaning fluid 63 afterthe switching valve 15 has been opened. This filling process is alsoterminated preferably after a predeterminable filling time T28.

Filling of the internal volumes during the cleaning steps S24, S26, andS28 usually causes cleaning fluid 63 to exit the test apparatus 1 viathe external connections 25, 27, 29. This exiting cleaning fluid 63 islead to a collecting container 89 via the fluid discharge lines 95 a, 95b, 95 c connected to the external connections 25, 27, 29. Preferably,the filling times T24, T26, and T28 are such that cleaning fluid exitsfrom all external connections 25, 27, 29 and flows to the collectingcontainer 89, so that it is advantageously ensured that all internalvolumes are filled with cleaning fluid 63.

In a subsequent cleaning step S30, the switching valves 13, 14 areclosed and the switching valve 12 is opened. In this state of the testapparatus 1, the cleaning fluid 63 resides within the internal volumes,so that contaminations can be removed from the walls of the internalvolumes by soaking or dissolving by means of the cleaning fluid 63. Inthis state, the test apparatus pauses for a predetermined orpredeterminable soaking time T30, which is preferably approx. 10 toapprox. 60 minutes.

At the end of the cleaning process, the switching valve 12 is closed ina cleaning step S32. To substantially drain the internal volumes filledwith the cleaning fluid 63, the following measures are conducted in astep S34. The compressed air valve 82 of the cleaning apparatus 3 isclosed and the connection 85 of the compressed air line 79 isdisconnected from the compressed air outlet 86, which is fluidicallycoupled with the compressed air valve 82. Preferably, this step has tobe performed and confirmed by the user. Subsequently, the fluiddischarge line 95 c at the connection for the collecting container 87 cis disconnected from the fluid supply 91 c of the collecting container89, and the fluid discharge line 95 c is fluidically coupled with thecompressed air outlet 86 by means of the connection 87 c. Alternatively,the compressed air supply line 79 at the compressed air connection 59could be disconnected from the compressed air intake 67 of the pressurecontainer 61 to couple the compressed air connection 59 with theexternal connection 29 of the test apparatus.

The fluid supply line 73 between the pressure container 61 and theexternal connection 23 of the test apparatus 1 is disconnected from thefluid exit 69 of the pressure container 61. Instead, the fluid supplyline 73 is coupled with the fluid connection 91 c of the collectingcontainer 89 by means of the connection 57.

FIG. 4 shows the arrangement of the test apparatus 1 and the cleaningapparatus 3 after step S34 has been performed. The following furtherdescription of the cleaning process thus relates to FIG. 4. The properestablishment of all fluid connections is preferably indicated to thesystem by a user input in a step S40.

To drain the internal volumes, the compressed air valve 82 is opened ina step S42, so that excess pressure builds up at the external connection29. The proper state of the test apparatus 1 and of the cleaningapparatus 3, in particular the tightness of all connections, isconfirmed by the user by a user input in a step S44.

After that, the switching valve 12 is opened in a step S46. By openingthe switching valve 12, the excess pressure applied to the externalconnection 29, which is provided by the compressed air source 77, isapplied to the internal volumes 51, 33, 49, V12, 37, 35, 39, 55, so thatsuccessive draining of the internal volumes can be started withsubsequently. In a step S48, the switching valve 13 is opened to drainthe internal reference tank 33 via the external connection 23. The draintime T48 is preferably at least approx. 120 seconds.

To drain the internal volumes V11, 35, 39, V13, 43, the switching valve12 is closed in a step S50, the switching valve 14 is opened, and theproportional valve 16 is at least partially, preferably approx. 50%,opened. The duration T50 of the pressure buildup is preferably approx.10 seconds. After that, in the step S50, the switching valve 11 isopened, and the switching valves 13, 14 are alternatingly opened andclosed, preferably for a duration of approx. 10 seconds. Furtherpreferably, the overlap time, during which both switching valves 13, 14are open or closed, is approx. 1 s or more. In this step S50, thecleaning fluid 63 can be drained from the volumes of the lines 35, 39,43, 41, 45, 47 and the volumes V13, V14, V15 of the switching valves 13,14, 15 via the external connections 23, 25, 27 into the collectingcontainer 89.

In a subsequent step S52, the switching valves 11, 14, 15 are opened andthe switching valves 12, 13 are closed, wherein the proportional valve16 remains opened preferably approx. 50%. Now, the switching valve 15 isopened and closed in an alternating manner, preferably at intervals ofapprox. 10 seconds, to drain the internal volumes of the switching valve15 and the lines 41, 45 via the external connection 25. The lines 47 aredrained alternatingly via the connection 27.

Subsequently, in step S54, all switching valves 11, 13, 14, 15 exceptfor the switching valve 12, which separates the internal reference tank33, and the proportional valve 16 are opened to drain all externalconnections 23, 25, 27 except for the external connection 29 for theexternal reference tank 31, which has already been drained via theinternal reference tank 33. After a predetermined or predeterminabledrain time, all switching valves 11, 12, 13, 14 and the proportionalvalve 16 are closed, while the switching valve 15, which is associatedwith the external vent 25, remains open. After the step S56 has beencompleted, flushing of the internal volumes is prepared.

After the test apparatus 1 has been drained, the flushing of theinternal volumes of the test apparatus 1 is prepared in a step S58. Tothis end, the compressed air valve 82 is closed and the test apparatus1, the cleaning apparatus 3, and the pressure container 61—as is shownin FIG. 2—are fluidically coupled with each other (step S59). Thisstructure corresponds to the structure shown in FIG. 2, which was usedto clean the test apparatus 1 by means of the cleaning fluid 63, whereininstead of the cleaning fluid 63, the pressure container 61 was filledwith a flushing fluid 65 different from the cleaning fluid 63, orwherein the pressure container 61 containing the cleaning fluid 63 wasexchanged for a pressure container 61 containing the flushing fluid 65.

As soon as the corresponding connections are correctly connected witheach other, the proper assembly of the test apparatus 1 with thecleaning apparatus 3 is confirmed by the user (step S60). Subsequently,in a step S62, the compressed air valve 82 is opened. The compressed airvalve 82 can be opened automatically or manually, wherein the opening ofthe compressed air valve 82 is then confirmed by the user in a step S64.

To fill the internal reference tank 33, the switching valves 12, 13 areopened in a step S66. The switching valve 15 is also open, while theswitching valves 11, 14 and the proportional valve 16 are closed. Aftera predetermined flushing time T66, the switching valve 12 is closed andthe switching valve 14 is opened to fill the internal volume of the testconnection 27 and the coupling line 47 with flushing fluid 65 in a stepS68. After a predetermined flushing time T68, the switching valve 15 isopened to fill the internal volumes of the coupling lines 41, 45 and theswitching valve 15 with the flushing fluid 65 in a step S70. Preferably,the cleaning steps S66, S68, and S70 can be repeated in an alternatingmanner. After that, the switching valves 12, 13, 14, 15 are opened toflush all external connections 23, 25, 27, 29 of the test apparatus 1with the flushing fluid 65 in a step S72. The flushing fluid 65 exitingthe test apparatus 1 during the flushing of the internal volumes is leadinto the collecting container 89 via the fluid discharge lines 95 a, 95b, 95 c. At the end of the flushing process, the switching valves 11,12, 13, 14, and 16 are closed in a step S74. Further, the compressed airvalve 82 is closed in a step S76, wherein the closing of the compressedair valve 82 is confirmed by the user in a step S78.

To drain the flushing fluid 65 off the internal volumes of the testapparatus 1 or to dry the internal volumes of the test apparatus 1, theconnection 85 of the compressed air line 79 is disconnected from thecompressed air outlet 86. Preferably, this step has to be performed andconfirmed by the user. Subsequently, the fluid discharge line 95 c atthe connection for the collecting container 87 c is disconnected fromthe fluid supply 91 c, and the fluid discharge line 95 c is fluidicallycoupled with the compressed air outlet 86 by means of the connection 87c. The fluid supply line 73 is removed from the pressure container 61.Instead, the fluid supply line 73 is coupled with the fluid connection91 c of the collecting container 89 by means of the connection 57.

To drain the flushing fluid 65 off the internal volumes of the testapparatus 1 or to dry the internal volumes of the test apparatus 1, thecompressed air supply line 79 can be disconnected from the pressurecontainer 61 as an alternative to the above-described procedure, tocouple the compressed air supply line 79 with the test apparatus 1,preferably by connecting the compressed air connection 59 with theconnection 29 for an external reference tank, wherefore the fluiddischarge line 95 c has been removed from this connection in advance.The fluid supply line 73 can also be removed, which is coupled with theconnection 23 of the test apparatus 1. The fluid discharge line 95 c isthen coupled with the connection 23.

This results in a structure as is shown in FIG. 4. The proper assemblyis confirmed by the user in a step S79.

Subsequently, the compressed air valve 82 is opened in a step S80, andthe opening of the compressed air valve 82 is confirmed by the user in astep S82.

In a first step S84 of drying the internal volumes of the test apparatus1, the switching valves 12, 13 are opened. After a predetermined orpredeterminable drying time T84 or preferably approx. 120 seconds, theswitching valve 12 is closed to suppress the flow of compressed airthrough the internal reference tank 33 in a drying step S86. Preferably,the switching valve 12 remains closed for a period of approx. 10 secondsduring the drying step S86. Further preferably, the steps S84 and S86are performed in an alternating manner. Further preferably, the stepsS84 and S86 are repeated approx. fifteen times.

Subsequently, in a step S88, the switching valves 11, 12, 14 are closedand the switching valves 13, 15 are opened. Furthermore, theproportional valve 16 is opened at least partially, preferably approx.50%. Since the switching valve 11 is closed, a pressure is build up viathe compressed air supply connection 21 and the proportional valve 16.After that, the switching valve 11 is opened and then, preferablyseveral times, the switching valves 13, 14 are opened and closed in analternating manner. Preferably, the opening and closing times of theswitching valves 13, 14 are approx. 10 seconds. Further preferably, theoverlap time during which both switching valves 12, 14 are open orclosed at the same time, is approx. 1 s. After a predetermined orpredeterminable drying time T80 of preferably approx. 2 minutes, thecleaning step S88 is terminated.

Subsequently, the switching valves 11, 14, 15 are opened and theswitching valves 12, 13 are closed. To dry the connection 25 for theexternal ventilation of the test apparatus 1, the switching valve 15 isalternatingly opened and closed in a step S90, wherein the opening andclosing times preferably are approx. 10 seconds. After a predetermineddrying time T90, the switching valves 11, 13, 14, 15 are opened and theswitching valve 12 is closed to dry all external connections 23, 25, 45,29 in a step S92. At the end of the drying process, the switching valves11, 12, 13, 14 and the proportional valve 16 are closed in a step S94.The compressed air valve 82 is also closed. The termination of thecleaning process can preferably be confirmed by a user. Furtherpreferably, the test apparatus can be put into a normal state aftercleaning, in which the switching valves 11, 14 and the proportionalvalve 16 are closed, while the switching valves 12, 13, 15 are open.

It is understood that the actuation of the compressed air valve 82 andthe establishment and disconnection of the corresponding required fluidconnections between the test apparatus 1, the cleaning apparatus 3, andthe pressure container 61 can be performed both manually by a user andautomatically by corresponding switching means. Accordingly, thecleaning process can be performed as a computer-assisted cleaningprocess or as a manual cleaning process.

Preferably, the cleaning process comprises the step of logging thecourse of the cleaning process, for example by storage on a datacarrier, by generating a printout of a cleaning protocol, or bytransmitting the cleaning protocol over a data line. Further preferably,the cleaning process comprises the step of determining the predeterminedor predeterminable times T24, T26, T28, T30, T48, T50, T66, T68, T80,T84, and T90, particularly by performing a test run.

FIG. 5 shows the schematic structure of a further preferred embodimentof a cleaning apparatus 3 for a test apparatus 1 for testing filtersand/or sterile disposable containers. The cleaning apparatus 3 isadapted to be operated with a first pressure container 61 a, whichcontains a cleaning fluid 63 during normal operation, and with a secondpressure container 61 b, which contains a flushing fluid 65 duringnormal operation. To this end, the cleaning apparatus 3 comprises afirst fluid connection 57 a and a first compressed air connection 59 afor the first pressure container 61 a, and a second fluid connection 57b and a second compressed air connection 59 b for the second pressurecontainer 61 b. The compressed air connections 59 a, 59 b and/or thefluid connections 57 a, 57 b are preferably formed or arranged in or ona housing 4 of the cleaning apparatus.

The first and second pressure containers 61 a, 61 b comprise acompressed air intake 67 a, 67 b, respectively, which can be coupledwith the associated compressed air connection 59 a, 59 b, and first andsecond fluid exits 69 a, 69 b, which can be coupled with the associatedfirst or second fluid connection 57 a, 57 b. Here, riser pipes 71 a, 71b are fluidically coupled with the associated fluid exits 69 a, 69 b,respectively. The riser pipes 71 a, 71 b preferably extend down to thebottoms of the pressure containers 61 a, 61 b. If the pressurecontainers 61 a, 61 b are fed with compressed air via the compressed airintakes 67 a, 67 b, excess pressure builds up within the pressurecontainers 61 a, 61 b, due to which the cleaning fluid 63 contained inthe pressure container 61 a or the flushing fluid 65 contained in thepressure container 61 b can rise within the riser tubes to escape fromthe pressure containers 61 a, 61 b through the fluid exits 69 a, 69 b.

To supply compressed air to the first and second pressure containers 61a, 61 b, the compressed air intakes 67 a, 67 b of the pressurecontainers 61 a, 61 b can be coupled with a compressed air source 77.Preferably, the compressed air intakes 67 a, 67 b are fluidicallycoupled with the compressed air source 77 via a common compressed airsupply line 79 and compressed air valve 82. The compressed air supplyline 79 can comprise a compressed air inlet 85 as well as a firstcompressed air connection 59 a for the first pressure container 61 a anda second compressed air connection 59 b for the second pressurecontainer 61 b. The compressed air valve 82 can be formed as aproportional valve, which is preferably controlled electrically, and canact as a pressure reducer. In particular, the compressed air source 77can be the same compressed air source 77 that provides the compressedair at the compressed air supply connection 21 of the test apparatus 1.Here, a T-connection 83 can be arranged between the compressed airsource 77 and the compressed air supply connection 21, so that thecompressed air supply connection 21 and the compressed air intake 67together are fluidically coupled with the pressure source 77. It isunderstood that both the compressed air valve 82 and the T-connection 83can be part of the cleaning apparatus 3, i.e. for example can bearranged at least partially in the housing 4 with other components ofthe cleaning apparatus 3. In this case, the cleaning apparatus 3 has acompressed air inlet and a compressed air supply line connection 84,which can be fluidically coupled with the compressed air supplyconnection 21 of the test apparatus 1. Preferably, the cleaningapparatus 3 can have a compressed air outlet 86 to which an externalcompressed air supply connection 79 can be coupled. Alternatively, thecompressed air valve 82 and/or the T-connection 83 can be designed asexternal components, wherein the compressed air is supplied to thecompressed air inlet 85 of the cleaning apparatus 3, which isfluidically coupled with the compressed air supply line 79, in a reducedor unreduced form. Further preferably, the compressed air sourceproduces a pressure of approx. 500 to approx. 900 kPa (5 to 9 bar),which is applied to the compressed air supply connection 21 of the testapparatus 1. The compressed air valve 82 is preferably designed oradjusted such that at the compressed air inlet 85 of the cleaningapparatus 3 or at the compressed air intakes 67 a, 67 b of the pressurecontainers 61 a, 61 b merely a pressure of approx. 100 to approx. 200kPa (1 to 2 bar), further preferably of approx. 2 bar, is applied.

Further preferably, the cleaning apparatus 3 comprises a pressure sensor130 and/or a moisture sensor 132, which is/are preferably fluidicallycoupled with the T-connection 83 to detect or measure the pressure ormoisture of the compressed air provided by the compressed air source 77.Both the pressure sensor 130 and the moisture sensor 132 can at leastpartially be arranged within the housing 4 or be formed or arrangedexternally. Advantageously, it can de determined by means of thepressure sensor 130 whether the compressed air source 77 provides thepreferred pressure of approx. 500 kPa to approx. 900 kPa. Thereby, thepressure of the compressed air required for a safe operation of the testapparatus 1 and the cleaning apparatus 3 can advantageously be detectedand monitored. Further preferably, the relative and/or absolute moistureof the provided compressed air can be detected or measured by means ofthe moisture sensor. Thereby, it can be checked, for example, whetherthe provided compressed air has a sufficiently low moisture content fordrying the internal volumes. Further preferably, at least one furthermoisture sensor can be provided, which is fluidically coupled with oneof the external connections 23, 25, 27 to detect or measure the moistureof the air exiting the internal volumes. Advantageously, the progress orthe quality of the drying process can be monitored or determined. Inparticular, the drying process can be terminated when the moisture ofthe exiting air reaches or falls below a predetermined threshold valuerelative to the moisture of the provided compressed air.

For the normal operation of the cleaning apparatus 3, the first fluidexit 69 a of the first pressure container 61 a can be coupledfluidically with one of the external connections 23, 25, 27, 29 of thetest apparatus 1, preferably with the connection 23 for internalventilation, via the first fluid connection 57 a and a fluid supply line73 a, a first fluid supply switching valve 99 a, and a fluid supply line73, wherein the connection can preferably be established by means of acomplementary or mating connection 75, for example by means of a plug-innipple or a plug-in coupling. Preferably, the cleaning apparatus 3 has atemperature and/or a pressure sensor (not shown), which is thermallyand/or fluidically coupled with the fluid supply line 73 to detect thetemperature and/or the pressure of the supplied cleaning fluid 63 orflushing fluid 65.

Accordingly, the second fluid exit 69 b of the second pressure container61 b can be coupled hydraulically with the above external connection 23via the second fluid connection 57 b and a fluid supply line 73 b, asecond fluid supply switching valve 99 b, and the fluid supply line 73.By means of the fluid supply switching valves 99 a, 99 b, it can becontrolled, preferably in a computer-assisted or automatic manner,whether the cleaning fluid 63 of the first pressure container 61 a orthe flushing fluid 65 of the second pressure container 61 b is suppliedto the test apparatus 1. A manual disconnection and coupling of thefluid lines is advantageously not required for that.

The cleaning apparatus 3 further comprises at least one connection 87 a,87 b, 87 c, 87 d for a collecting container 89, which during normaloperation collects the fluids exiting or flowing out of the internalvolumes 35, 49, 51, 43, 47, 45, 37, 39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄,V₁₅ of the test apparatus 1. The collecting container 89 comprises atleast one fluid supply 91 a, 91 b, 91 c, 91 d and a vent 93. For thenormal operation of the cleaning apparatus 3, the at least one fluidsupply 91 a, 91 b, 91 c, 91 d of the collecting container 89 can befluidically coupled with one of the external connections 23, 25, 27, 29of the test apparatus 1 via at least one fluid discharge line 95 a andone fluid discharge connection 97 a, wherein the fluid dischargeconnection 97 a is preferably a connection that is complementary to therespective external connection 23, 25, 27, 29, for example a plug-innipple or a plug-in coupling. It is understood that also a plurality ofexternal connections 23, 25, 27, 29 of the test apparatus 1 can becoupled with an associated fluid supply 91 a, 91 b, 91 c, 91 d of thecollecting container 89 via an associated fluid discharge line 95 a, 95b, 95 c, 95 d via fluid discharge connections 97 a, 97 b, 97 c.

To advantageously prevent excess pressure from building up in thecollecting container 89, at least one vent 93 is provided to allow thegaseous phase of the fluid supplied to the collecting container 89 andthe air displaced by the fluid in the connecting container to escapeinto the environment. To prevent the test apparatus 1 from beingcontaminated by a fluid flowing back from the collecting container 89,the fluid supplies 91 a, 91 b, 91 c, 91 d are preferably provided with acheck valve. Particularly preferably, the fluid supplies 91 a, 91 b, 91c, 91 d are formed as plug-in nipples or plug-in couplings, which eachhave a closure valve and/or a check valve. Alternatively, a closurevalve and/or a check valve can be arranged in a complementary plug-incoupling or a complementary plug-in nipple of the connections 87 a, 87b, 87 c, 87 d of the fluid discharge lines 95 a, 95 b, 95 c, 95 d.Further preferably, a bacteria-retaining apparatus or a virus-retainingapparatus 101 is arranged downstream of the vent 93 to advantageouslyprevent the environment from being contaminated by pathogenic germsexiting the test apparatus. The bacteria-retaining apparatus or thevirus-retaining apparatus 101 can be fluidically coupled with the vent93 particularly by means of a retaining apparatus connection 88,particularly be fluidically coupled in a sterile manner. Preferably, thebacteria-retaining apparatus or the virus-retaining apparatus 101 is atleast partially arranged within the housing 4 of the cleaning apparatus3, as is shown in FIG. 2, wherein the retaining apparatus connection 88is preferably arranged or formed in or on the housing 4. Alternatively,the bacteria or virus-retaining apparatus 101 can also be arranged as anexternal apparatus outside the housing.

To enable both the filling of the internal volumes of the test apparatus1 with a cleaning fluid 63 or a flushing fluid 65 via the complementaryconnection 75 and the draining into the collecting container 89 via oneof the fluid discharge connections 97 d, the cleaning apparatus 3comprises a first outlet switching valve 103, which is controlled in anopposite manner to the first and second fluid supply switching valves 99a, 99 b. In this case, the complementary connection 75 and the fluiddischarge connection 97 d are identical and coupled with the externalconnection 23 for internal ventilation of the test apparatus 1. Thefirst discharge switching valve 103 is closed when at least one of thetwo fluid supply switching valves 99 a, 99 b is opened. Contrary, thefirst discharge switching valve 103 is only opened when both fluidsupply switching valves 99 a, 99 b are closed. Thus, a contamination ofthe cleaning fluid 63 in the pressure container 61 a and of the flushingfluid 65 in the pressure container 61 b by fluid flowing back canadvantageously prevented.

To further enable both the supply of compressed air to the externalconnection 29 for the external reference tank via the fluid dischargeconnection 97 a and the drainage into the collecting container 89, thecleaning apparatus 3 comprises a second discharge switching valve 105,which is controlled in an opposite manner to a compressed air supplyswitching valve 107. In other words, the second discharge switchingvalve 105 is closed when the compressed air supply switching valve 107is opened, and vice versa. Thus, a contamination of the compressed airsupply line 79 by fluid flowing back can advantageously be prevented.

Alternatively or in addition to the compressed air supply switchingvalve 107, a first bypass valve 115 a can be arranged between the firstfluid connection 57 a and the first compressed air connection 59 a forthe first container 61 a to enable the supply of compressed air via theexternal connection 23 of the test apparatus 1. Further alternatively orin addition to the compressed air supply switching valve 107 and/or thefirst bypass valve 115 a, a second bypass valve 115 b can be arrangedbetween the second fluid connection 57 b and the second compressed airconnection 59 b for the second container 61 b to enable the supply ofcompressed air via the external connection 23 of the test apparatus.

Preferably, the cleaning apparatus 3 can have a hot steam supplyconnection 122, which can be particularly formed or arranged in or onthe housing 4. The hot steam supply connection 122 is adapted to befluidically coupled with a hot steam connection 124 of a hot steamgenerator 125. Hot steam generated by the hot steam generator 125 can besupplied to the cleaning apparatus 3 via the hot steam supply connection122 and a hot steam switching valve 120. It is understood that the hotsteam generator 125 can alternatively be formed within the housing 4 ofthe cleaning apparatus 3.

Via the compressed air supply line 79 and the compressed air supplyswitching valve 107, the hot steam can be supplied either directly tothe test apparatus 1 via the external connection 29 or be supplied tothe external connection 23 via at least one of the pressure containers61 a, 61 b, the fluid supply lines 73 a, 73 b. Advantageously, asterilization of the internal volumes can be performed by means of thehot steam. Particularly preferably, a sterilization of the pressurecontainer(s) 61 a, 61 b can be performed by supplying hot steam via oneof the pressure containers 61 a, 61 b or via both pressure containers 61a, 61 b at the same time.

FIG. 6 shows a flow diagram of a preferred automatic, particularlycomputer-assisted, cleaning process with reference to FIGS. 1 and 5. Itis understood that switching of the valves cannot only be performedautomatically, but also manually. Preferably, a user is interactivelyrequested to take several actions at the beginning of and optionallyduring the cleaning process, for example, couple tubes to specificexternal connections, and to subsequently confirm these actions via aninput unit (not shown). Further preferably, switching of the valves isperformed automatically according to a cleaning program to be selected.

At the beginning of the cleaning process, the test apparatus 1 ispreferably in a normal state, wherein the switching valves 11, 14 andthe proportional valve 16 are closed and the switching valves 12, 13, 15are open. In an initialization step S110, a first pressure container 61a is filled with a cleaning fluid 63 and a second pressure container 61b is filled with a flushing fluid 65. The compressed air intakes 67 a,67 b and the fluid exits 69 a, 69 b of the pressure containers 61 a, 61b are coupled with the associated compressed air connections 59 a, 59 band fluid connections 57 a, 57 a, respectively, of the cleaningapparatus 3. Further preferably, the required complementary externalconnections 75, 84, 97 a, 97 b, 97 c, 97 d of the cleaning apparatus 3are coupled with the associated external connections 21, 23, 25, 27, 29of the test apparatus 1. This can preferably be done by means of aconnection device 109, which can be coupled with a complementaryconnection device 111 (as is shown in FIGS. 7 a and 7 b) of the testapparatus 1. The cleaning apparatus 3 is in an initial state, whereinthe compressed air valve 82, the first 99 a and second 99 b fluid supplyswitching valves, the first 103 and second 105 discharge switchingvalves, and the compressed air supply switching valve 107 are closed.The correct coupling of the cleaning apparatus 3 with the test apparatus1 is confirmed by the user via the input unit, for example by actuatinga start button (not shown).

The steps of the cleaning process described in the following arepreferably performed automatically without any further user input. Thetest apparatus 1 is put into a start state for cleaning, wherein theswitching valves 11, 12, 13, 14 and the proportional valve 16 areclosed, while the switching valve 15 remains open (step S112).

After the cleaning process has been started, the compressed air valve 82is opened in a step S120, so that compressed air from the compressed airsource 77 gets into the pressure containers 61 a, 61 b via theT-connection 83, the compressed air valve 82, and the compressed airline 79. Thereby, excess pressure builds up within the pressurecontainers 61 a, 61 b, which preferably is approx. 1.1 to 2 bar, furtherpreferably approx. 2 bar. In a step S124, the first fluid supplyswitching valve 99 a, the switching valves 12, 13 are opened and theswitching valve 15 is closed to fill the internal reference tank 33 withthe cleaning fluid 63 from the pressure container 61 a. In doing so, dueto the excess pressure in the pressure container 61 a, i.e. by pneumaticconveyance, the cleaning fluid 63 rises through the riser pipe 71 a viathe fluid supply lines 73 a, 73 to the external connection 23 forinternal ventilation of the test apparatus 1. Starting from the externalconnection 23, the cleaning fluid 63 flows to the internal referencetank 33 via the line 43, the switching valve 13, the lines 39, 35, 37,the switching valve 12, and the line 49. From there, the cleaning fluid63 can flow further via the line 51 and from the external connection 29out of the test apparatus. Filling of the internal reference tank 33 ispreferably determined by means of a predetermined or predeterminablefilling time T124.

Subsequently, after the internal reference tank 33 has been filled, theexternal connection 27, which is adapted for connection of a filter 5 ora container 7, is filled with cleaning fluid in a step S126. To thisend, in step S126, the switching valve 12 is closed and the switchingvalve 14 is opened, so that the cleaning fluid 63 can flow to theexternal connection 27 via the line 35, the switching valve 14, and theline 47. Preferably, the filling process is time-controlled and thusterminated after a predetermined or predeterminable filling time T126.Finally, in a step S128, the remaining part of the internal volumes,i.e. the line 41, the switching valve 15, and the line 45, are filledwith the cleaning fluid 63 after the switching valve 15 has been opened.This filling process is also terminated preferably after a predeterminedor predeterminable filling time T128.

Filling of the internal volumes during the cleaning steps S124, S126,and S128 usually causes cleaning fluid 63 to exit the test apparatus 1via the external connections 25, 27, 29. This exiting cleaning fluid 63is lead to a collecting container 89 via the fluid discharge lines 95 a,95 b, 95 c connected to the external connections 25, 27, 29. Preferably,the filling times T24, T26, and T28 are such that cleaning fluid exitsfrom all external connections 25, 27, 29 and flows to the collectingcontainer 89, so that it is advantageously ensured that all internalvolumes are filled with cleaning fluid 63 and all contaminations arealready flushed out.

In a subsequent cleaning step S130, the switching valves 13, 14 areclosed and the switching valve 12 is opened. In this state of the testapparatus 1, the cleaning fluid 63 resides temporarily within theinternal volumes, so that contaminations can be removed from the wallsof the internal volumes by soaking or dissolving by means of thecleaning fluid 63. In this state, the test apparatus pauses for apredetermined soaking time T130, which is preferably approx. 10 toapprox. 60 minutes.

At the end of the cleaning process, the switching valve 12 is closed ina cleaning step S132. To drain the internal volumes filled with thecleaning fluid 63, the following measures are conducted in a step S146.The first fluid supply switching valve 99 a and the second dischargeswitching valve 105 are closed, while the first discharge valve 103 andthe compressed air supply switching valve 107 are opened. Thereby, theexternal connection 29 of the test apparatus 1 is supplied withcompressed air via the compressed air line 79, the compressed air supplyswitching valve 107, and the fluid discharge line 95 c. After theswitching valve 12 has been opened, the excess pressure applied to theexternal connection 29, which is provided by the compressed air source77, is applied to the internal volumes 51, 33, 49, V₁₂, 37, 35, 39, 55,so that successive draining of the internal volumes can be started withsubsequently. In a step S148, the switching valve 13 is opened to drainthe internal reference tank 33 via the external connection 23. The draintime T148 is preferably at least approx. 120 seconds.

To drain the internal volumes V₁₁, 35, 39, V₁₃, 43, the switching valve12 is closed in a step S150, the switching valve 14 is opened, and theproportional valve 16 is at least partially, preferably approx. 50%,opened. The duration T150 of the pressure buildup is preferably approx.10 seconds. After that, in the step S150, the switching valve 11 isopened, and the switching valves 13, 14 are alternatingly opened andclosed, preferably for a duration of approx. 10 seconds. Furtherpreferably, the overlap time, during which both switching valves 13, 14are open or closed, is approx. 1 s or more. In this step S150, thecleaning fluid can be drained from the volumes of the lines 35, 39, 43,41, 45, 47 and the volumes V₁₃, V₁₄, V₁₅ of the switching valves 13, 14,15 via the external connections 23, 25, 27 into the collecting container89.

In a subsequent step S152, the switching valves 11, 14, 15 are openedand the switching valves 12, 13 are closed, wherein the proportionalvalve 16 remains opened preferably approx. 50%. Now, the switching valve15 is opened and closed in an alternating manner, preferably atintervals of approx. 10 seconds, to drain the internal volumes of theswitching valve 15 and the lines 41, 45, 47 via the external connections25, 27.

Subsequently, all switching valves 11, 13, 14, 15 except for theswitching valve 12, which separates the internal reference tank 33, andthe proportional valve 16 are opened to drain all external connections23, 25, 27 except for the external connection 29 for the externalreference tank 31, which has already been drained via the internalreference tank 33. After a predetermined or predeterminable drain time,all switching valves 11, 12, 14 and the proportional valve 16 areclosed, while the switching valve 15, which is associated with theexternal vent 25, and the switching valve 13, which is associated withthe internal vent 23, remain open. After the step S156 has beencompleted, flushing of the internal volumes is prepared.

After the test apparatus 1 has been drained, the flushing of theinternal volumes of the test apparatus 1 is prepared in a step S162. Thecompressed air valve 82, the first discharge valve 103, and thecompressed air supply switching valve 107 are closed and the secondfluid supply switching valve 99 b and the second discharge switchingvalve 105 are opened. Thereby, flushing fluid 65 from the secondpressure container 61 b can be pneumatically conveyed to the externalconnection 23 of the test apparatus 1. Subsequently, the compressed airvalve 82 is opened.

To fill the internal reference tank 33, the switching valves 12, 13 areopened in a step S166. The switching valve 15 is also open, while theswitching valves 11, 14 and the proportional valve 16 are closed. Aftera predetermined flushing time T166, the switching valve 12 is closed andthe switching valve 14 is opened to fill the internal volume of the testconnection 27 and the coupling line 47 with flushing fluid 65 in a stepS168. After a predetermined flushing time T168, the switching valve 15is opened to fill the internal volumes of the coupling lines 41, 45 andthe switching valve 15 with the flushing fluid 65 in a step S170.Preferably, the cleaning steps S66, S68, and S170 can be repeated in analternating manner. After that, the switching valves 12, 13, 14, 15 areopened to flush all external connections 23, 25, 27, 29 of the testapparatus 1 with the flushing fluid 65 in a step S172. The flushingfluid 65 exiting the test apparatus 1 during the flushing of theinternal volumes is lead into the collecting container 89 via the fluiddischarge lines 95 a, 95 b, 95 c. At the end of the flushing process,the switching valves 11, 12, 13, 14, and 16 and the compressed air valve82 are closed.

Preferably, after the step S172, a drainage and sterilization of theinternal volumes can be performed. By analogy with steps S146 to S156,draining is performed in the steps S146′ to S156′. As for thedescription of the steps S146′ to S156′ described in FIG. 6, referenceis made to the previous description of the steps S146 to S156.Subsequently, sterilization can be performed by means of hot steam. Forsterilization, in a step S183, the compressed air valve 82 is closed andthe hot steam switching valve 120 coming from the internal or externalhot steam generator 125 is opened. Preferably, at least one of thecompletely drained pressure containers 61 a, 61 b can be flown throughby hot steam. To this end, preferably all internal valves 11 to 16 areclosed and merely the fluid supply switching valves 99 a, 99 b and thefirst discharge switching valve 103 are open. Preferably, also thesecond discharge switching valve 105 and the compressed air supplyswitching valve 107 are opened in a period of approx. 60 seconds,preferably approx. 120 seconds, for approx. 10 seconds each in order tosufficiently sterilize the fluid discharge line 95 c and the portion ofthe compressed air supply line 79 arranged between the compressed airsupply switching valve 107 and the fluid discharge line 95 c. Theoverall duration of the above-described step 183 of sterilizing ispreferably 30 to 60 minutes. This process is optional; the pressurecontainers 61 a, 61 b might as well be autoclaved separately.

In the further course, the internal volumes of the test apparatus 1 canbe sterilized. The steps S184′ to S194′ shown in FIG. 6 correspond tothe steps of drying S184 to S194. As for the description of the stepsS184′ to S194′ described in FIG. 6, reference is made to the previousdescription of the steps S184 to S194, wherein the following preferreddeviation takes place: The step 184′ lasts until the requiredsterilization temperature of approx. 121° C., preferably approx. 134°C., has been reached in the internal reference tank 33 of the testapparatus. This step then lasts for a further period of 30 to 60minutes. It is followed by the steps 188′ to 192′ for a total time ofpreferably 30 to 60 minutes. Particularly, the temperature of theexiting fluid and/or the temperature in the internal reference tank canbe monitored by means of the preferred temperature sensor in order toincrease the sterilization duration and the duration of times in whichthe required temperature of approx. 121° C. or 134° C. is fallen below.

To drain the flushing fluid 65 from the internal volumes of the testapparatus 1 or to dry the internal volumes of the test apparatus 1, thefollowing measures are conducted in a step S184. The second fluid supplyswitching valve 99 b and the second discharge switching valve 105 areclosed, while the first discharge valve 103 and the compressed airsupply switching valve 107 are opened. Thereby, the external connection29 of the test apparatus 1 is supplied with compressed air via thecompressed air line 79, the compressed air supply switching valve 107,and the fluid discharge line 95 c. In a step S186 of drying the internalvolumes of the test apparatus 1, the switching valves 12, 13 are opened.After a predetermined or predeterminable drying time T86 or preferablyapprox. 120 seconds, the switching valve 12 is closed to suppress theflow of compressed air through the internal reference tank 33.Preferably, the switching valve 12 remains closed for a time or approx.10 seconds. Further preferably, opening and closing of the switchingvalve 12 is performed in an alternating manner and further preferablyrepeated approx. five to fifteen times.

Subsequently, in a step S188, the switching valves 11, 12, 14 are closedand the switching valves 13, 15 are opened. Furthermore, theproportional valve 16 is opened at least partially, preferably approx.50%. Since the switching valve 11 is closed, a pressure is build up viathe compressed air supply connection 21 and the proportional valve 16.After that, the switching valve 11 is opened and then, preferablyseveral times, the switching valves 13, 14 are opened and closed in analternating manner. Preferably, the opening and closing times of theswitching valves 13, 14 are approx. 10 seconds. Further preferably, theoverlap time during which both switching valves 12, 14 are open orclosed at the same time, is approx. 1 s. After a predetermined orpredeterminable drying time T188 of preferably approx. 2 minutes, thecleaning step S188 is terminated.

Subsequently, the switching valves 11, 14, 15 are opened and theswitching valves 12, 13 are closed. To dry the connection 25 for theexternal ventilation of the test apparatus 1, the switching valve 15 isalternatingly opened and closed in a step S190, wherein the opening andclosing times preferably are approx. 10 seconds. After a predeterminedor predeterminable drying time T190, the switching valves 11, 13, 14, 15are opened and the switching valve 12 is closed to dry all externalconnections 23, 25, 29 in a step S192. At the end of the drying process,the switching valves 11, 12, 13, 14 and the proportional valve 16 areclosed in a step S194. The compressed air valve 82 is also closed. Thesuccessful termination of the cleaning process can preferably beconfirmed by a user. Further preferably, the test apparatus can be putinto a normal state after cleaning, in which the switching valves 11, 14and the proportional valve 16 are closed, while the switching valves 12,13, 15 are open.

Preferably, the cleaning process comprises the step of logging thecourse of the cleaning process, for example by storage on a datacarrier, by generating a printout of a cleaning protocol, or bytransmitting the cleaning protocol over a data line. Further preferably,the cleaning process comprises the step of determining the predeterminedor predeterminable times T124, T126, T128, T130, T148, T150, T166, T168,T188, and T190, particularly by performing a test run.

The FIGS. 7 a and 7 b show a preferred embodiment of a test apparatus 1with a complementary connection device 111 for connection of theconnection device of the cleaning apparatus. In the illustratedembodiment, the external connections 21, 23, 25, 27, 29 of the testapparatus 1 are arranged on the complementary connection device 111 in afixed, geometrical arrangement to each other, so that an associated ormating connection device of a cleaning apparatus can be coupled with thecomplementary connection device 111 in a simple manner.

Preferably, the connection device of the cleaning apparatus can bearranged on the test apparatus 1 by a displacement movement along theconnection direction A, particularly by a linear displacement, such thatthe complementary external connections of the connection device can befluidically coupled with the associated external connections 21, 23, 25,27, 29 of the test apparatus 1. Advantageously, the required connectionscan be established quickly and erroneous connections can be avoided.

It is understood that the control of the switching means, i.e. of thevalves, can be performed automatically or in a computer-assisted mannerduring the cleaning process described with reference to FIGS. 3 and 6.Particularly, the control of the switching means can be performed by asingle, non-illustrated control unit, which may be located in the testapparatus 1 or in the cleaning apparatus 3, or via two control units incommunication with each other, wherein one of the two control units islocated in the test apparatus 1 and the other is located in the cleaningapparatus 3. Therefore, preferably at least one electrical connection isprovided between the test apparatus 1 and the cleaning apparatus 3,particularly to transmit the control signals.

The electrical connection between the test apparatus 1 and the cleaningapparatus can preferably be established by electrically contacting orconnecting at least one connector of the cleaning apparatus with anassociated complementary connector 113 of the test apparatus 1.Preferably, the electrical connection can be established by displacingthe cleaning apparatus along the connection direction A, particularly bya linear displacement. Particularly, the electrical connection can havean interface, for example a RS232 interface, a RS435 interface, a RJ45interface and/or a USB interface, with which preferably a data transferbetween the cleaning apparatus and the test apparatus 1 can take place.Further preferably, the electrical connection can also take care of thecurrent supply of the cleaning apparatus. Advantageously, a power supplyin the cleaning apparatus can be omitted then.

Further preferably, the complementary connection device 111 of the testapparatus 1 comprises the complementary connector 113. Accordingly, theconnection device of the cleaning apparatus can comprise the connector,so that advantageously both the fluidic and the electrical connectionbetween the test apparatus 1 and the associated cleaning apparatus canbe established in a particularly simple manner by means of theconnection device and the complementary connection device 111.

What is claimed is:
 1. A test apparatus (1) for testing filters (5) orcontainers (7), comprising: switching means (11, 12, 13, 14, 15);external connections (21, 23, 25, 27, 29); internal volumes (35, 49, 51,43, 47, 45, 37, 39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅), which can comeinto contact with a fluid from a filter (5) or container (7) to betested; wherein the switching means (11, 12, 13, 14, 15) themselves andthe switching means (11, 12, 13, 14, 15) and the external connections(21, 23, 25, 27, 29) are fluidically coupled via the internal volumes(35, 49, 51, 43, 47, 45, 37, 39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅),and wherein the internal volumes (35, 49, 51, 43, 47, 45, 37, 39, 41,55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅) of the test apparatus (1) are arrangedsuch that the internal volumes (35, 49, 51, 43, 47, 45, 37, 39, 41, 55,33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅) can be substantially completely drained viaone of the external connections (23, 25, 27, 29), which is arranged atthe lowest point with respect to the internal volumes (35, 49, 51, 43,47, 45, 37, 39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅).
 2. The testapparatus (1) of claim 1, wherein the internal volumes (35, 49, 51, 43,47, 45, 37, 39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅) are arranged suchthat the path from the lowest point of the internal volumes (35, 49, 51,43, 47, 45, 37, 39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅) to an arbitraryfurther point within the internal volumes (35, 49, 51, 43, 47, 45, 37,39, 41, 55, 33, V₁₁, V₁₂, V₁₃, V₁₄, V₁₅) increases steadily opposite tothe direction of gravity in parts, or has a constant height with respectto the direction of gravity at least in parts.